A 26-year-old male patient presented with features suggestive of osteomyelitis involving the entire left femur, hip joint and knee joint. Culture from the debrided tissue grew Acinetobacter spp. and he was treated with sensitivity based antibiotics but the symptoms did not resolve. The synovial biopsy showed multinucleated giant cells and acid fast bacilli on Ziehl Neelsen stain. Cartridge based nucleic acid amplification test (GeneXpert) was negative. The Mycobacteria growth indicator tube culture was found to be positive for Mycobacterium abscessus...

BACKGROUND: Mycobacterium abscessus has been implicated as the cause of various infections in the setting of healthcare-related "outbreaks." Mandibular osteomyelitis caused by M abscessus is exceedingly rare, with only 1 patient reported in the literature. The authors describe the surgical management of 12 pediatric patients with M abscessus-related mandibular osteomyelitis and cervical lymphadenitis caused by exposure to contaminated water at a regional dental clinic. METHODS: Following institutional review board approval, new suspected patients were reviewed and followed prospectively...

M. abscessus complex is notoriously resistant to most antimicrobial agents. The complex is differentiated into 3 subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. abscessus subsp. bolletii. Skin and soft tissue infections due to this organism can be acquired by direct contact with contaminated material through traumatic injury, surgical wound and environmental exposure or by secondary involvement of skin/soft tissue during disseminated disease. We report a case of Mycobacterium abscessus infection recovered from a post-operative mid-line abdominal wound to illustrate the diagnostic and management difficulties encountered in such patients...

Mycobacterium abscessus is a fast-growing environmental organism and an important emerging pathogen. It is highly resistant to many antibiotics and undergoes a smooth to rough colony morphology change that appears to be important for pathogenesis. Smooth environmental strains have a glycopeptidolipid (GPL) on the surface, while certain types of clinical strains are often rough and lack this GPL, due to mutations in biosynthetic genes or the mmpL4b transporter gene. We report here the development and evaluation of an allelic exchange system for unmarked alleles in M...

The applications of whole-metagenome shotgun sequencing (WMGS) in routine clinical analysis are still limited. A combination of a DNA extraction procedure, sequencing, and bioinformatics tools is essential for the removal of human DNA and for improving bacterial species identification in a timely manner. We tackled these issues with a broncho-alveolar lavage (BAL) sample from an immunocompromised patient who had developed severe chronic pneumonia. We extracted DNA from the BAL sample with protocols based either on sequential lysis of human and bacterial cells or on the mechanical disruption of all cells...

Lung disease caused by Mycobacterium abscessus is increasing and current clarithromycin-based treatment regimens are only moderately effective. Here, we determined the effect of clarithromycin-vancomycin combination against M. abscessus complex isolates in vitro. Synergy was found with an FICI ≤ 0.5 and a 4 to 10-fold decrease of minimum inhibitory concentrations.

The most common infections caused by nontuberculous mycobacteria (NTM) are lung infections. The microorganisms causing these infections most frequently are Mycobacterium avium complex, Mycobacterium kansasii and Mycobacterium abscessus complex. Their incidence has increased in the last three decades. After identifying an NTM in the respiratory tract, clinical and radiological aspects must be considered to determine if isolations are clinically relevant. Predisposing conditions that could contribute to infection must also be investigated...

Mycobacterium abscessus is a rapidly growing mycobacterium (RGM) causing serious infections especially among cystic fibrosis patients. Extremely limited therapeutic options against M. abscessus and a rise in infections with this mycobacterium require novel chemotherapies and a better understanding of how the bacterium causes infection. Different from most RGM, M. abscessus can survive inside macrophages and persist for long durations in infected tissues. We recently delineated differences in the infective programs followed by smooth (S) and rough (R) variants of M...

BACKGROUND: Outbreaks of infections caused by rapidly growing mycobacteria have been reported worldwide generally associated with medical procedures. Mycobacterium abscessus subsp. massiliense CRM0019 was obtained during an epidemic of postsurgical infections and was characterized by increased persistence in vivo. To better understand the successful survival strategies of this microorganism, we evaluated its infectivity and proliferation in macrophages (RAW and BMDM) and alveolar epithelial cells (A549)...

Background: Mycobacterium abscessus is an uncommon cause of invasive odontogenic infection. Methods: M abscessus-associated odontogenic infections occurred in a group of children after they each underwent a pulpotomy. A probable case-child was defined as a child with facial or neck swelling and biopsy-confirmed granulomatous inflammation after a pulpotomy between October 1, 2013, and September 30, 2015. M abscessus was isolated by culture in confirmed case-children...

BACKGROUND: Mycobacterium abscessus is one of the most antibiotic-resistant pathogens in Cystic Fibrosis (CF) patients. Nitric Oxide (NO) has broad-spectrum antimicrobial activity. Clinical studies indicated that it is safe and tolerable when given as 160 ppm intermittent inhalations. METHODS: A prospective compassionate adjunctive inhaled NO therapy in two CF patients with persistent Mycobacterium abscessus infection. RESULTS: No adverse events were reported...

An epidemic of post-surgical wound infections, caused by a non-tuberculous mycobacterium, has been on-going in Brazil. It has been unclear whether one or multiple lineages are responsible and whether their wide geographical distribution across Brazil is due to spread from a single point source or is the result of human-mediated transmission. 188 isolates, collected from nine Brazilian states, were whole genome sequenced and analysed using phylogenetic and comparative genomic approaches. The isolates from Brazil formed a single clade, which was estimated to have emerged in 2003...

Combinations of antibiotics, each individually effective against Mycobacterium abscessus, are routinely co-administered based on the concept that this minimizes the spread of antibiotic resistance. However, our in vitro data contradicts this assumption and instead documents antagonistic interactions between two antibiotics (clarithromycin and amikacin) used to treat M. abscessus infections. Clinically relevant concentrations of clarithromycin induced increased resistance to both amikacin and itself. Induction of resistance was dependent on whiB7, a transcriptional activator of intrinsic antibiotic resistance that is induced by exposure to many different antibiotics...

Mycobacterium abscessus causes acute and chronic broncho-pulmonary infection in patients with chronic lung damage, of which cystic fibrosis (CF) patients are particularly vulnerable. The major threat posed by this organism is its high intrinsic antibiotic resistance. A typical treatment regimen involves a 6-12 month long combination therapy of clarithromycin and amikacin, with cure rates below 50% and multiple side effects, especially due to amikacin. In the present work we show that M. abscessuswhiB7, a homologue of M...

To characterize members of the Mycobacterium abscessus complex, with an emphasis on the correlation between species identification and clarithromycin associated genetic polymorphisms that contribute to inducible and constitutive macrolide resistance. PCR and sequencing analysis was used to elucidate the subspecies, erm(41) genotypes and the presence of rrl mutations. M. abscessus subsp. massiliense was the dominant subspecies (70.2 %), followed by M. abscessus subsp. abscessus (23.8 %) and M. abscessus subsp...

The prevalence of lung disease due to infections with nontuberculous mycobacteria (NTM) has been increasing and surpassed tuberculosis (TB) in some countries. Treatment outcomes are often unsatisfactory, highlighting an urgent need for new anti-NTM medications. Although NTM in general do not respond well to TB specific drugs, the similarities between NTM and Mycobacterium tuberculosis at the molecular and cell structural level suggest that compound libraries active against TB could be leveraged for NTM drug discovery...

PURPOSE OF REVIEW: In cystic fibrosis (CF) patients with end-stage pulmonary disease, lung transplantation (LTx) remains a life-extending therapy with good outcome in most patients. Despite early concern about chronic pretransplantation infections in the context of posttransplantation immunosuppression, typical CF-associated organisms such as Pseudomonas aeruginosa turned out to be quite well manageable and associated with favorable outcomes in transplanted CF patients, even in patients with highly resistant strains...

Mycobacteriaceae comprises pathogenic species such as Mycobacterium tuberculosis, M. leprae and M. abscessus, as well as non-pathogenic species, for example, M. smegmatis and M. thermoresistibile. Genome comparison and annotation studies provide insights into genome evolutionary relatedness, identify unique and pathogenicity-related genes in each species, and explore new targets that could be used for developing new diagnostics and therapeutics. Here, we present a comparative analysis of ten-mycobacterial genomes with the objective of identifying similarities and differences between pathogenic and non-pathogenic species...

Mycobacterium abscessus (MAB) is a species of nontuberculous mycobacteria (NTM) and a major causative pathogen of pulmonary diseases especially in patients with cystic fibrosis. MAB infection is notoriously difficult to treat because of its intrinsic or inducible resistance to most antibiotics. The rough (R) morphotype of MAB, lacking cell surface glycopeptidolipids (GPLs), is associated with more severe and persistent infection than the smooth (S) type; however, the mechanisms underlying the R type's virulence and the relation with GPLs remain unclear...

TheMycobacterium abscessus complex is a group of rapidly growing, multiresistant mycobacteria previously divided into three species. Proposal for the union of Mycobacterium bolletii and Mycobacterium massiliense into one subspecies, so-called M. abscessus subsp. massiliense, created much confusion about the routine identification and reporting of M. abscessus clinical isolates for clinicians. Results derived from multigene sequencing unambiguously supported the reinstatement of M. massiliense and M. bolletii as species, culminating in the presence of erm(41)-encoded macrolide resistance in M...